This project is a randomized controlled trial to evaluate the efficacy of a group exercise and health promotion program designed specifically for older adults with Mild Cognitive Impairment (MCI). It is a competitive renewal of RO1#AG14777, (Problem Solving/Physical Intervention &Aging), an intervention aimed at promoting independence in physically frail, cognitively intact older adults, and its supplement, a feasibility trial of a modified version of the intervention (now called RALLI--Resources &Activities for Life Long Independence) for older adults with MCI. Findings from both studies indicated significant positive treatment outcomes, including increased muscle strength, endurance, and exercise time;improved physical functioning, self-reported health perceptions, depression, quality of life, well-being, vitality, and perceived self-control. For participants with MCI in the feasibility trial, after 9-weeks participation in RALLI, mean exercise time increased by 172 minutes per week, HDL cholesterol significantly improved, and mean MMSE scores improved by 1.2 points. This investigation will compare RALLI to an existing community-based exercise control condition for older adults (Lifetime Fitness-LF). Participants will be over age 70, community residing, and meet criteria for MCI and insufficient physical activity. They will be evaluated at baseline, post-treatment, and every 6 months for 36 months by interviewers blind to treatment condition. Primary and secondary outcomes include cognitive decline, affective and physical function, self-rated health and health behaviors, and quality of life. Exploratory outcomes include 36-month rate of conversion from MCI to dementia, level of physical disability, continuation in independent living, and physiological health indicators. We hypothesize that RALLI participants will experience better post-treatment outcomes than LF subjects, and that RALLI participants will have a lower rate of conversion to dementia and less physical and functional decline over 36 months. Significance to Public Health: This proposal will investigate the efficacy of an exercise and health promotion program designed to preserve cognitive and physical function in older adults with mild cognitive impairment. These older adults are at increased risk of developing Alzheimer's disease within 3 years, and delaying or preventing cognitive decline will preserve their ability to live independently and save public health dollars.